supplementary materials


hb6552 scheme

Acta Cryst. (2012). E68, o225    [ doi:10.1107/S1600536811054432 ]

Methylammonium tetrafluoridoborate 18-crown-6 clathrate

Y. Jin

Abstract top

In the title compound, CH3NH3+·BF4-·C12H24O6, the methylammonium cation makes three N-H...O hydrogen bonds to the 18-crown-6 molecule. The -NH3+ and -CH3 groups of the cation adopt a staggered conformation. The F atoms of the tetrafluoridoborate anion are disordered over two sets of sites in a 0.519 (11):0.481 (11) ratio. Weak C-H...F interactions occur in the crystal, which possibly correlate with the anion disorder.

Comment top

Molecular motion has proved to cause a rotation of the local structure to give rise to the formation of reversible structural phase transition from high-temperature disordered state to low temperature ordered state. Only a small part of compounds in which the components can be arranged in a disordered status at a relative high temperature and in an ordered one at a relative low temperature have been found until now. The transition from the disordered arrangement to the ordered one results in sharp change in the physical properties of compounds (e.g. Wu et al., 2011). The protonated CH3—NH3+ cation can be easily anchored in the cavity of 18-crown-6, as a result of strong N—H···O hydrogen-bonding interactions. In the protonated CH3—NH3+, –NH3+ can be fixed firmly by 18-crown-6 which is an excellent molecular-based stator via N—H···O hydrogen-bonding interactions forming a stationary axis along which the rest of CH3—NH3+ cation can rotate freely. The introduction of a disordered group in the compounds results in the potential for the order-disorder transition due to the fact that the freezing of a disordered group at low temperature forces significant orientational motions of the group and thus may induce the formation of the ferroelectric phase. As part of our search for simple ferroelectric compounds we have investigated the title compound and reported its room temperature structure.

In this crystal structure, the nitrogen of the –NH3+ group lies 1.043 Å from the plane of the O atoms of the crown ring, in contrast to the analogous complex (Henschel et al., 1999) and analogous perchlorate hemihytrate (Trueblood et al., 1982), where the corresponding distance is 0.981 Å and 0.68 Å individually.

The anion and one cation are shown in Fig. 1 with the hydrogen bonds listed in Table 1. The existence of N—H···O hydrogen-bonding interactions and weak C—H···F interactions helps to make the substance more stable, and thus forms a three-dimensional structure. The components are held together by N—H···O hydrogen bonds and weak C—H···F interactions, forming a 1:1:1 aggregate. The aggregates are further connected by weak C—H···F interactions, and thus forms a complex spatial geometry.

Related literature top

For related structures, see: Henschel et al. (1999); Trueblood et al. (1982). For the possible relationship of the title compound to molecular ferroelectrics, see: Wu et al. (2011).

Experimental top

(C12H24O6.CH3NH3+).(BF-4) was formed from a mixture of C12H24O6 (264.32 mg, 1.00 mmol), CH3NH2 (8 mL, 40% aqueous solution), tetrafluoridoborate (10 mL, 48% aqueous solution) and distilled water (5 ml), which was stirred a few minutes at room temperature, giving a clear transparent solution. After evaporation for a few days, block colorless crystals suitable for X-ray diffraction were obtained in about 60% yield and filtered and washed with distilled water.

Refinement top

H atoms bound to carbon and nitrogen were placed at idealized positions [C—H = 0.96–0.97 Å, N—H = 0.89 Å] and allowed to ride on their parent atoms with Uiso fixed at 1.2 Ueq(C,N).

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level.
[Figure 2] Fig. 2. Crystal structure of the title compound with view along the c axis. Intermolecular interactions are shown as dashed lines.
Methylammonium tetrafluoroborate–1,4,7,10,13,16-hexaoxacyclooctadecane (1/1) top
Crystal data top
CH6N+·BF4·C12H24O6F(000) = 1632
Mr = 383.19Dx = 1.285 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 3450 reflections
a = 24.375 (5) Åθ = 6.2–55.3°
b = 8.5404 (17) ŵ = 0.12 mm1
c = 21.345 (4) ÅT = 293 K
β = 116.90 (3)°Block, colorless
V = 3962.7 (14) Å30.3 × 0.3 × 0.2 mm
Z = 8
Data collection top
Rigaku Mercury CCD
diffractometer
4519 independent reflections
Radiation source: fine-focus sealed tube2155 reflections with I > 2σ(I)
graphiteRint = 0.061
ω scansθmax = 27.5°, θmin = 3.1°
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
h = 3131
Tmin = 0.489, Tmax = 1.000k = 1111
19676 measured reflectionsl = 2727
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.073Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.226H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0967P)2 + 1.8449P]
where P = (Fo2 + 2Fc2)/3
4519 reflections(Δ/σ)max < 0.001
265 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.19 e Å3
Crystal data top
CH6N+·BF4·C12H24O6V = 3962.7 (14) Å3
Mr = 383.19Z = 8
Monoclinic, C2/cMo Kα radiation
a = 24.375 (5) ŵ = 0.12 mm1
b = 8.5404 (17) ÅT = 293 K
c = 21.345 (4) Å0.3 × 0.3 × 0.2 mm
β = 116.90 (3)°
Data collection top
Rigaku Mercury CCD
diffractometer
4519 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
2155 reflections with I > 2σ(I)
Tmin = 0.489, Tmax = 1.000Rint = 0.061
19676 measured reflectionsθmax = 27.5°
Refinement top
R[F2 > 2σ(F2)] = 0.073H-atom parameters constrained
wR(F2) = 0.226Δρmax = 0.25 e Å3
S = 1.03Δρmin = 0.19 e Å3
4519 reflectionsAbsolute structure: ?
265 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
B10.0812 (2)0.6121 (6)0.4200 (2)0.0824 (12)
C10.09781 (16)0.9413 (5)0.04075 (16)0.0815 (11)
H1D0.13610.98480.04510.098*
H1E0.06660.95470.00740.098*
C20.10575 (15)0.7737 (4)0.05902 (16)0.0798 (10)
H2A0.06840.73240.05840.096*
H2B0.11380.71620.02490.096*
C30.16487 (15)0.5967 (4)0.14898 (18)0.0713 (9)
H3A0.17170.53390.11530.086*
H3B0.12850.55730.15130.086*
C40.21812 (15)0.5856 (3)0.21816 (19)0.0710 (9)
H4A0.22850.47640.23020.085*
H4B0.25320.63670.21710.085*
C50.25467 (14)0.6571 (4)0.33741 (17)0.0726 (9)
H5A0.28880.71450.33690.087*
H5B0.26790.55000.35130.087*
C60.23720 (16)0.7287 (4)0.38822 (16)0.0786 (11)
H6A0.20140.67570.38670.094*
H6B0.27070.71830.43530.094*
C70.2087 (2)0.9725 (5)0.41965 (19)0.0952 (12)
H7A0.24180.96020.46680.114*
H7B0.17150.92910.41850.114*
C80.1995 (2)1.1415 (5)0.4007 (2)0.1035 (14)
H8A0.19151.19870.43490.124*
H8B0.23641.18430.40070.124*
C90.1367 (3)1.3161 (4)0.3089 (3)0.1140 (16)
H9A0.17221.35900.30580.137*
H9B0.12941.37820.34240.137*
C100.0821 (3)1.3234 (5)0.2390 (3)0.1215 (18)
H10A0.04771.26910.24050.146*
H10B0.07021.43160.22610.146*
C110.04701 (16)1.2532 (5)0.1191 (3)0.1032 (15)
H11A0.03361.36000.10490.124*
H11B0.01261.19440.11830.124*
C120.06760 (16)1.1822 (4)0.0705 (2)0.0937 (13)
H12A0.03601.19440.02240.112*
H12B0.10451.23440.07490.112*
C130.06353 (16)0.8461 (5)0.2238 (2)0.0916 (12)
H13A0.07190.79700.26770.137*
H13B0.04850.76930.18700.137*
H13C0.03310.92640.21370.137*
F10.0811 (5)0.6402 (13)0.3601 (5)0.131 (3)0.481 (11)
F20.1331 (3)0.5661 (14)0.4620 (5)0.165 (5)0.481 (11)
F30.1255 (7)0.705 (3)0.4670 (9)0.198 (8)0.481 (11)
F40.0293 (5)0.6160 (16)0.4217 (8)0.156 (5)0.481 (11)
F1'0.0550 (4)0.5665 (13)0.3505 (4)0.128 (3)0.519 (11)
F2'0.1037 (8)0.4578 (13)0.4316 (7)0.245 (7)0.519 (11)
F3'0.0814 (5)0.7788 (7)0.4154 (6)0.131 (3)0.519 (11)
F4'0.0385 (5)0.5822 (11)0.4440 (7)0.134 (4)0.519 (11)
N10.12000 (9)0.9158 (2)0.22837 (11)0.0495 (6)
H1A0.13250.99170.26040.074*
H1B0.11280.95530.18680.074*
H1C0.14910.84270.24080.074*
O10.15612 (9)0.7548 (2)0.12755 (10)0.0627 (6)
O20.20466 (8)0.6585 (2)0.27007 (10)0.0589 (5)
O30.22339 (9)0.8921 (2)0.37129 (10)0.0678 (6)
O40.14840 (12)1.1580 (3)0.33206 (15)0.0861 (8)
O50.09714 (10)1.2516 (2)0.18839 (14)0.0836 (7)
O60.07986 (9)1.0197 (3)0.08667 (11)0.0745 (6)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
B10.093 (4)0.091 (4)0.079 (3)0.017 (3)0.052 (3)0.021 (3)
C10.077 (2)0.108 (3)0.0402 (17)0.023 (2)0.0092 (16)0.0027 (17)
C20.072 (2)0.099 (3)0.0504 (18)0.0180 (19)0.0124 (17)0.0165 (18)
C30.072 (2)0.0590 (19)0.086 (2)0.0001 (16)0.0379 (19)0.0157 (17)
C40.074 (2)0.0512 (17)0.102 (3)0.0160 (15)0.052 (2)0.0005 (17)
C50.0608 (19)0.0652 (19)0.072 (2)0.0068 (15)0.0130 (17)0.0232 (16)
C60.080 (2)0.079 (2)0.0510 (18)0.0188 (18)0.0075 (17)0.0282 (17)
C70.113 (3)0.119 (3)0.062 (2)0.033 (3)0.047 (2)0.015 (2)
C80.140 (4)0.108 (3)0.087 (3)0.042 (3)0.072 (3)0.049 (2)
C90.170 (5)0.060 (2)0.163 (5)0.000 (3)0.119 (4)0.030 (3)
C100.143 (4)0.060 (2)0.209 (6)0.039 (3)0.121 (5)0.017 (3)
C110.053 (2)0.070 (2)0.160 (4)0.0206 (18)0.025 (3)0.047 (3)
C120.0542 (19)0.087 (3)0.100 (3)0.0011 (19)0.000 (2)0.055 (2)
C130.071 (2)0.091 (3)0.121 (3)0.0077 (19)0.051 (2)0.014 (2)
F10.164 (8)0.154 (8)0.084 (5)0.001 (5)0.064 (6)0.024 (5)
F20.077 (4)0.167 (9)0.153 (7)0.012 (5)0.035 (4)0.070 (6)
F30.143 (9)0.293 (16)0.188 (12)0.136 (11)0.102 (9)0.138 (13)
F40.087 (5)0.236 (12)0.166 (9)0.025 (5)0.076 (5)0.021 (7)
F1'0.125 (6)0.157 (8)0.095 (4)0.004 (4)0.044 (4)0.051 (5)
F2'0.445 (18)0.148 (8)0.296 (12)0.147 (10)0.302 (14)0.114 (8)
F3'0.156 (7)0.091 (4)0.154 (6)0.039 (4)0.077 (6)0.006 (4)
F4'0.207 (10)0.103 (4)0.173 (8)0.099 (6)0.156 (8)0.088 (5)
N10.0497 (12)0.0450 (12)0.0531 (13)0.0062 (10)0.0227 (11)0.0051 (10)
O10.0595 (12)0.0602 (13)0.0624 (13)0.0057 (9)0.0223 (10)0.0088 (10)
O20.0451 (10)0.0542 (11)0.0685 (13)0.0106 (8)0.0178 (10)0.0096 (9)
O30.0808 (14)0.0767 (14)0.0451 (11)0.0172 (11)0.0277 (10)0.0049 (10)
O40.115 (2)0.0612 (14)0.110 (2)0.0184 (13)0.0749 (18)0.0261 (13)
O50.0680 (14)0.0553 (13)0.130 (2)0.0189 (11)0.0476 (15)0.0133 (13)
O60.0686 (14)0.0717 (14)0.0649 (13)0.0036 (11)0.0140 (11)0.0222 (11)
Geometric parameters (Å, °) top
B1—F21.238 (8)C7—O31.414 (4)
B1—F41.281 (11)C7—C81.489 (6)
B1—F11.299 (9)C7—H7A0.9700
B1—F31.348 (8)C7—H7B0.9700
B1—F4'1.376 (10)C8—O41.437 (5)
B1—F1'1.380 (8)C8—H8A0.9700
B1—F2'1.406 (9)C8—H8B0.9700
B1—F3'1.428 (7)C9—O41.422 (5)
C1—O61.410 (4)C9—C101.486 (7)
C1—C21.474 (5)C9—H9A0.9700
C1—H1D0.9700C9—H9B0.9700
C1—H1E0.9700C10—O51.427 (5)
C2—O11.431 (4)C10—H10A0.9700
C2—H2A0.9700C10—H10B0.9700
C2—H2B0.9700C11—O51.430 (5)
C3—O11.411 (3)C11—C121.473 (6)
C3—C41.463 (5)C11—H11A0.9700
C3—H3A0.9700C11—H11B0.9700
C3—H3B0.9700C12—O61.429 (4)
C4—O21.432 (3)C12—H12A0.9700
C4—H4A0.9700C12—H12B0.9700
C4—H4B0.9700C13—N11.461 (4)
C5—O21.402 (3)C13—H13A0.9600
C5—C61.466 (5)C13—H13B0.9600
C5—H5A0.9700C13—H13C0.9600
C5—H5B0.9700N1—H1A0.8900
C6—O31.443 (4)N1—H1B0.8900
C6—H6A0.9700N1—H1C0.8900
C6—H6B0.9700
F2—B1—F4133.3 (10)O3—C6—H6A109.8
F2—B1—F1108.5 (8)C5—C6—H6A109.8
F4—B1—F1117.4 (9)O3—C6—H6B109.8
F2—B1—F355.5 (12)C5—C6—H6B109.8
F4—B1—F3115.6 (8)H6A—C6—H6B108.3
F1—B1—F3105.5 (7)O3—C7—C8109.2 (3)
F2—B1—F4'111.6 (8)O3—C7—H7A109.8
F4—B1—F4'21.9 (12)C8—C7—H7A109.8
F1—B1—F4'137.4 (8)O3—C7—H7B109.8
F3—B1—F4'108.6 (6)C8—C7—H7B109.8
F2—B1—F1'120.9 (8)H7A—C7—H7B108.3
F4—B1—F1'93.2 (8)O4—C8—C7109.0 (3)
F1—B1—F1'36.9 (4)O4—C8—H8A109.9
F3—B1—F1'142.3 (7)C7—C8—H8A109.9
F4'—B1—F1'106.7 (6)O4—C8—H8B109.9
F2—B1—F2'52.0 (7)C7—C8—H8B109.9
F4—B1—F2'109.4 (10)H8A—C8—H8B108.3
F1—B1—F2'100.0 (6)O4—C9—C10109.7 (4)
F3—B1—F2'107.4 (16)O4—C9—H9A109.7
F4'—B1—F2'93.6 (8)C10—C9—H9A109.7
F1'—B1—F2'83.0 (9)O4—C9—H9B109.7
F2—B1—F3'109.4 (8)C10—C9—H9B109.7
F4—B1—F3'90.6 (7)H9A—C9—H9B108.2
F1—B1—F3'75.4 (6)O5—C10—C9108.8 (3)
F3—B1—F3'55.9 (9)O5—C10—H10A109.9
F4'—B1—F3'103.7 (6)C9—C10—H10A109.9
F1'—B1—F3'102.9 (6)O5—C10—H10B109.9
F2'—B1—F3'159.0 (10)C9—C10—H10B109.9
O6—C1—C2108.8 (3)H10A—C10—H10B108.3
O6—C1—H1D109.9O5—C11—C12108.7 (3)
C2—C1—H1D109.9O5—C11—H11A109.9
O6—C1—H1E109.9C12—C11—H11A109.9
C2—C1—H1E109.9O5—C11—H11B109.9
H1D—C1—H1E108.3C12—C11—H11B109.9
O1—C2—C1109.2 (2)H11A—C11—H11B108.3
O1—C2—H2A109.8O6—C12—C11109.2 (3)
C1—C2—H2A109.8O6—C12—H12A109.8
O1—C2—H2B109.8C11—C12—H12A109.8
C1—C2—H2B109.8O6—C12—H12B109.8
H2A—C2—H2B108.3C11—C12—H12B109.8
O1—C3—C4108.9 (2)H12A—C12—H12B108.3
O1—C3—H3A109.9N1—C13—H13A109.5
C4—C3—H3A109.9N1—C13—H13B109.5
O1—C3—H3B109.9H13A—C13—H13B109.5
C4—C3—H3B109.9N1—C13—H13C109.5
H3A—C3—H3B108.3H13A—C13—H13C109.5
O2—C4—C3110.1 (2)H13B—C13—H13C109.5
O2—C4—H4A109.6C13—N1—H1A109.5
C3—C4—H4A109.6C13—N1—H1B109.5
O2—C4—H4B109.6H1A—N1—H1B109.5
C3—C4—H4B109.6C13—N1—H1C109.5
H4A—C4—H4B108.2H1A—N1—H1C109.5
O2—C5—C6110.2 (3)H1B—N1—H1C109.5
O2—C5—H5A109.6C3—O1—C2111.9 (2)
C6—C5—H5A109.6C5—O2—C4113.1 (2)
O2—C5—H5B109.6C7—O3—C6113.2 (3)
C6—C5—H5B109.6C9—O4—C8113.1 (3)
H5A—C5—H5B108.1C10—O5—C11112.7 (3)
O3—C6—C5109.3 (2)C1—O6—C12112.9 (3)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H1C···O20.891.982.867 (3)171
N1—H1B···O60.891.992.866 (3)168
N1—H1A···O40.891.992.876 (3)171
C2—H2B···F2'i0.972.413.345 (14)163
C7—H7B···F3'0.972.523.481 (13)172
C9—H9B···F1'ii0.972.493.306 (12)142
C9—H9B···F2'ii0.972.363.298 (17)163
C11—H11A···F4'iii0.972.473.393 (12)158
Symmetry codes: (i) x, −y+1, z−1/2; (ii) x, y+1, z; (iii) −x, y+1, −z+1/2.
Table 1
Hydrogen-bond geometry (Å, °)
top
D—H···AD—HH···AD···AD—H···A
N1—H1C···O20.891.982.867 (3)171
N1—H1B···O60.891.992.866 (3)168
N1—H1A···O40.891.992.876 (3)171
C2—H2B···F2'i0.972.413.345 (14)163
C7—H7B···F3'0.972.523.481 (13)172
C9—H9B···F1'ii0.972.493.306 (12)142
C9—H9B···F2'ii0.972.363.298 (17)163
C11—H11A···F4'iii0.972.473.393 (12)158
Symmetry codes: (i) x, −y+1, z−1/2; (ii) x, y+1, z; (iii) −x, y+1, −z+1/2.
Acknowledgements top

The author thanks Southeast University for support.

references
References top

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Wu, D.-H., Ge, J.-Z., Cai, H.-L., Zhang, W. & Xiong, R.-G. (2011). CrystEngComm, 13, 319–324.